The London Stock Exchange will replace its troubled TradElect platform with a system from Sri Lankan supplier MillenniumIT, according to reports.

The exchange refused to comment on its plans. The existing LSE TradElect platform suffered serious reliability issues last year, when network software problems took it offline for a potentially devastating seven hours. At the time, angry traders stormed out of the exchange in protest.

The system is also alleged to be slower than those at rival exchanges.

The £40 million TradElect system was upgraded by Accenture a year ago. It runs on HP ProLiant Servers and Microsoft .Net and SQL Server 2000 systems, within a Cisco network architecture.

Tower Group analyst Bob McDowall told Computer Weekly – which first reported the news – that he was surprised at the choice of new platform. He said he expected a provider with more of “a track record in Europe” to be chosen.

But the system is currently in use at the London Metal Exchange, and stock exchanges on other continents. And MillenniumIT claims on its website that it has developed the “world’s fastest” trading platform, running on Intel Xeon 5500 processors, and potentially delivering transaction times of 0.13 milliseconds.

The company has said it will be possible to process one million orders per second “using volume produced Intel two socket Nehalem servers”, within a commercially affordable environment.

The current trading speed on TradElect is only 2.7 milliseconds, compared to 0.4 milliseconds at specialist electronic rival Chi-X, the Wall Street Journal stated in an article last month.

Xavier Rolet, the new chief executive at the LSE, said in August that the exchange would install a platform that could execute electronic trades in “sub millisecond” times, as well as cut costs.

The LSE has been testing alternatives to TradElect for some months. It is understood that even if a choice has not yet been made, a decision will be reached soon.

In June, the Financial Times speculated that an off-the-shelf platform would be chosen, suggesting there had been a strained relationship between the LSE and external IT consultants and developers. It blamed the exchange for “relying” on such suppliers to build and maintain its systems over the years.

Cost is understood to be an additional factor motivating the change, with nearly half of the LSE’s current annual expenditure dedicated to technology. But the LSE has not stated how much it will spend.

Accenture and MillenniumIT had not returned calls for comment at the time of writing.